1. Field of the Invention
The present invention relates to a portable electronic device.
2. Description of the Related Art
There exist biological information detecting devices detecting a biological signal by attaching a sensor electrode to a biological surface. In this kind of biological information detecting devices, there is the one which measures a heart rate from the biological surface, for example, by detecting an electrocardiographic signal generated by heartbeats by the sensor electrode. As such a biological information detecting device, for example, there is the one which includes a sensor electrode and a device body (transmission unit) transmitting an electrocardiographic signal detected by the sensor electrode to the outside. The heart rate is measured by a separate receiving unit receiving the signal transmitted from the device body.
The sensor electrode and the device body are attached to a user's body by using a ring-shaped band having elasticity such as a rubber band. The user puts on the sensor electrode and the device body so that the ring-shaped band is attached around the body. Accordingly, the sensor electrode is pressed onto the biological surface and the electrocardiographic signal can be detected. It is necessary that the sensor electrode is held at a predetermined position in the body which is suitable for detecting the electrocardiographic signal during the use for positively detecting the electrocardiographic signal.
When the sensor electrode is held so as not to be displaced during exercise and so on, the user may feel a sense of oppression as a tightening force by the band is high.
In response to the above, a structure in which a band with a sensor electrode is integrally attached to a garment is disclosed in, for example, Japanese Patent No. 4721700 (Patent Literature 1).
Moreover, a structure in which a sensor electrode is woven into a garment as part of the garment by using conductive yarn is disclosed in, for example, Japanese Patent No. 5176202 (Patent Literature 2).
As shown in Patent Literatures 1 and 2, as the sensor electrode is integrally attached to the garment, a position of the sensor electrode with respect to the body is not largely displaced when the user wears the garment on the body.
However, in the structures disclosed in Patent Literatures 1 and 2, the sensor electrode is easily deteriorated by washing of the garment or the like as the sensor electrode is attached to the garment. Accordingly, there is room for improvement in extension of lifetime of the biological information detecting device.
The position of the sensor electrode is determined by a position where the sensor band is woven into the garment. Therefore, the sensor electrode is not always arranged in an appropriate position with respect to the body in the state where the garment is worn on the body due to the individual difference even when the user selects the garment in the appropriate size for the user's body. Additionally, as the sensor electrode is previously provided in the garment, it is difficult to adjust the position of the sensor electrode so as to correspond to the user, therefore, the degree of freedom in the attachment position is low. Therefore, there is a danger that detection performance in the sensor electrode is reduced when the position of the sensor electrode is inappropriate. The position of the sensor electrode may give uncomfortable feeling to the user in the state where the user puts on the sensor, which may cause a problem in wearing feeling.
It can be considered that other various electronic devices such as a music player are attached to the garment in the same manner, not limited to the biological information detecting device. Also in this case, the above-described problems exist in common.